diff --git a/homeassistant/components/alexa/handlers.py b/homeassistant/components/alexa/handlers.py
index eb23b09627e..c1b99b017e5 100644
--- a/homeassistant/components/alexa/handlers.py
+++ b/homeassistant/components/alexa/handlers.py
@@ -857,14 +857,55 @@ async def async_api_adjust_target_temp(
     temp_delta = temperature_from_object(
         hass, directive.payload["targetSetpointDelta"], interval=True
     )
-    target_temp = float(entity.attributes.get(ATTR_TEMPERATURE)) + temp_delta
-
-    if target_temp < min_temp or target_temp > max_temp:
-        raise AlexaTempRangeError(hass, target_temp, min_temp, max_temp)
-
-    data = {ATTR_ENTITY_ID: entity.entity_id, ATTR_TEMPERATURE: target_temp}
 
     response = directive.response()
+
+    current_target_temp_high = entity.attributes.get(climate.ATTR_TARGET_TEMP_HIGH)
+    current_target_temp_low = entity.attributes.get(climate.ATTR_TARGET_TEMP_LOW)
+    if current_target_temp_high and current_target_temp_low:
+        target_temp_high = float(current_target_temp_high) + temp_delta
+        if target_temp_high < min_temp or target_temp_high > max_temp:
+            raise AlexaTempRangeError(hass, target_temp_high, min_temp, max_temp)
+
+        target_temp_low = float(current_target_temp_low) + temp_delta
+        if target_temp_low < min_temp or target_temp_low > max_temp:
+            raise AlexaTempRangeError(hass, target_temp_low, min_temp, max_temp)
+
+        data = {
+            ATTR_ENTITY_ID: entity.entity_id,
+            climate.ATTR_TARGET_TEMP_HIGH: target_temp_high,
+            climate.ATTR_TARGET_TEMP_LOW: target_temp_low,
+        }
+
+        response.add_context_property(
+            {
+                "name": "upperSetpoint",
+                "namespace": "Alexa.ThermostatController",
+                "value": {"value": target_temp_high, "scale": API_TEMP_UNITS[unit]},
+            }
+        )
+        response.add_context_property(
+            {
+                "name": "lowerSetpoint",
+                "namespace": "Alexa.ThermostatController",
+                "value": {"value": target_temp_low, "scale": API_TEMP_UNITS[unit]},
+            }
+        )
+    else:
+        target_temp = float(entity.attributes.get(ATTR_TEMPERATURE)) + temp_delta
+
+        if target_temp < min_temp or target_temp > max_temp:
+            raise AlexaTempRangeError(hass, target_temp, min_temp, max_temp)
+
+        data = {ATTR_ENTITY_ID: entity.entity_id, ATTR_TEMPERATURE: target_temp}
+        response.add_context_property(
+            {
+                "name": "targetSetpoint",
+                "namespace": "Alexa.ThermostatController",
+                "value": {"value": target_temp, "scale": API_TEMP_UNITS[unit]},
+            }
+        )
+
     await hass.services.async_call(
         entity.domain,
         climate.SERVICE_SET_TEMPERATURE,
@@ -872,13 +913,6 @@ async def async_api_adjust_target_temp(
         blocking=False,
         context=context,
     )
-    response.add_context_property(
-        {
-            "name": "targetSetpoint",
-            "namespace": "Alexa.ThermostatController",
-            "value": {"value": target_temp, "scale": API_TEMP_UNITS[unit]},
-        }
-    )
 
     return response
 
diff --git a/tests/components/alexa/test_smart_home.py b/tests/components/alexa/test_smart_home.py
index a1f77a9b49b..a2dcdedd470 100644
--- a/tests/components/alexa/test_smart_home.py
+++ b/tests/components/alexa/test_smart_home.py
@@ -2176,8 +2176,8 @@ async def test_thermostat(hass: HomeAssistant) -> None:
         "cool",
         {
             "temperature": 70.0,
-            "target_temp_high": 80.0,
-            "target_temp_low": 60.0,
+            "target_temp_high": None,
+            "target_temp_low": None,
             "current_temperature": 75.0,
             "friendly_name": "Test Thermostat",
             "supported_features": 1 | 2 | 4 | 128,
@@ -2439,6 +2439,103 @@ async def test_thermostat(hass: HomeAssistant) -> None:
     assert call.data["preset_mode"] == "eco"
 
 
+async def test_thermostat_dual(hass: HomeAssistant) -> None:
+    """Test thermostat discovery with auto mode, with upper and lower target temperatures."""
+    hass.config.units = US_CUSTOMARY_SYSTEM
+    device = (
+        "climate.test_thermostat",
+        "auto",
+        {
+            "temperature": None,
+            "target_temp_high": 80.0,
+            "target_temp_low": 60.0,
+            "current_temperature": 75.0,
+            "friendly_name": "Test Thermostat",
+            "supported_features": 1 | 2 | 4 | 128,
+            "hvac_modes": ["off", "heat", "cool", "auto", "dry", "fan_only"],
+            "preset_mode": None,
+            "preset_modes": ["eco"],
+            "min_temp": 50,
+            "max_temp": 90,
+        },
+    )
+    appliance = await discovery_test(device, hass)
+
+    assert appliance["endpointId"] == "climate#test_thermostat"
+    assert appliance["displayCategories"][0] == "THERMOSTAT"
+    assert appliance["friendlyName"] == "Test Thermostat"
+
+    assert_endpoint_capabilities(
+        appliance,
+        "Alexa.PowerController",
+        "Alexa.ThermostatController",
+        "Alexa.TemperatureSensor",
+        "Alexa.EndpointHealth",
+        "Alexa",
+    )
+
+    properties = await reported_properties(hass, "climate#test_thermostat")
+    properties.assert_equal("Alexa.ThermostatController", "thermostatMode", "AUTO")
+    properties.assert_equal(
+        "Alexa.ThermostatController",
+        "upperSetpoint",
+        {"value": 80.0, "scale": "FAHRENHEIT"},
+    )
+    properties.assert_equal(
+        "Alexa.ThermostatController",
+        "lowerSetpoint",
+        {"value": 60.0, "scale": "FAHRENHEIT"},
+    )
+    properties.assert_equal(
+        "Alexa.TemperatureSensor", "temperature", {"value": 75.0, "scale": "FAHRENHEIT"}
+    )
+
+    # Adjust temperature when in auto mode
+    call, msg = await assert_request_calls_service(
+        "Alexa.ThermostatController",
+        "AdjustTargetTemperature",
+        "climate#test_thermostat",
+        "climate.set_temperature",
+        hass,
+        payload={"targetSetpointDelta": {"value": -5.0, "scale": "KELVIN"}},
+    )
+    assert call.data["target_temp_high"] == 71.0
+    assert call.data["target_temp_low"] == 51.0
+    properties = ReportedProperties(msg["context"]["properties"])
+    properties.assert_equal(
+        "Alexa.ThermostatController",
+        "upperSetpoint",
+        {"value": 71.0, "scale": "FAHRENHEIT"},
+    )
+    properties.assert_equal(
+        "Alexa.ThermostatController",
+        "lowerSetpoint",
+        {"value": 51.0, "scale": "FAHRENHEIT"},
+    )
+
+    # Fails if the upper setpoint goes too high
+    msg = await assert_request_fails(
+        "Alexa.ThermostatController",
+        "AdjustTargetTemperature",
+        "climate#test_thermostat",
+        "climate.set_temperature",
+        hass,
+        payload={"targetSetpointDelta": {"value": 6.0, "scale": "CELSIUS"}},
+    )
+    assert msg["event"]["payload"]["type"] == "TEMPERATURE_VALUE_OUT_OF_RANGE"
+
+    # Fails if the lower setpoint goes too low
+    msg = await assert_request_fails(
+        "Alexa.ThermostatController",
+        "AdjustTargetTemperature",
+        "climate#test_thermostat",
+        "climate.set_temperature",
+        hass,
+        payload={"targetSetpointDelta": {"value": -6.0, "scale": "CELSIUS"}},
+    )
+    assert msg["event"]["payload"]["type"] == "TEMPERATURE_VALUE_OUT_OF_RANGE"
+
+
 async def test_exclude_filters(hass: HomeAssistant) -> None:
     """Test exclusion filters."""
     request = get_new_request("Alexa.Discovery", "Discover")